No exploitation reportedFix available

CVE-2021-29485

Q: Is CVE-2021-29485 actively exploited?

Active exploitation of CVE-2021-29485 has not been confirmed. Its EPSS score was 2.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-29485?

CVE-2021-29485 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-06-29
Fixed in1.9.0
WeaknessCWE-502

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, a malicious attacker can achieve Remote Code Execution (RCE) via a maliciously crafted Java deserialization gadget chain leveraged against the Ratpack session store. If one's application does not use Ratpack's session mechanism, it is not vulnerable. Ratpack 1.9.0 introduces a strict allow-list mechanism that mitigates this vulnerability when used. Two possible workarounds exist. The simplest mitigation for users of earlier versions is to reduce the likelihood of attackers being able to write to the session data store. Alternatively or additionally, the allow-list mechanism could be manually back ported by providing an alternative implementation of `SessionSerializer` that uses an allow-list.

Timeline

dates in UTC

2021-06-2919:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-29485?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-29485?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Ratpack project ratpack

Branch	Affected	Fixed in	Source
1.9	< 1.9.0	1.9.0	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Ratpack project ratpack to 1.9.0

Advisories and patches

mvnrepository.comRelease Notes

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.19.9read 2026-10-23
NVDCVSS 3.18.8read 2026-10-23
NVDCVSS 2.06.5read 2026-10-23
CNAweakness (CWE)CWE-502read 2026-10-23
NVDweakness (CWE)CWE-502read 2026-10-23
FIRST EPSSEPSS score2.0 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published: 2021-06-29
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-29485?

Is CVE-2021-29485 actively exploited?

Active exploitation of CVE-2021-29485 has not been confirmed. Its EPSS score was 2.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-29485?

CVE-2021-29485 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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